RU2032635C1 - Method for cement clinker production - Google Patents

Abstract

FIELD: building materials production. SUBSTANCE: crushed raw material is decarbonized and then its grinding at 1150-1350 C is carried out. Final roasting followed by cooling is carried out. Mentioned above high temperature grinding takes place when carbon dioxide and bound water are removed of the material. EFFECT: decreases energy expense. 3 tbl

Description

 The invention relates to methods for firing cement clinker and can be used in the construction materials industry.

The closest in technical essence and the achieved result is a method for producing cement clinker, including the preparation of the raw mix with solid fuel, its grinding, high-speed high-temperature decarbonization at 1150-1350 ^о С, firing in a rotary kiln and cooling.

The disadvantage of this method is that the grinding of raw materials containing 30-45% CO ₂ and chemically bound water is carried out before decarbonization of the material, which results in increased energy consumption for grinding.

 The aim of the invention is to reduce energy consumption for grinding.

The goal is achieved in that in the method for producing cement clinker, comprising preparing the raw material mixture, grinding it, decarbonization speed at a high temperature ^of 1150-1350 C in the rotary kiln calcining and cooling of the product in which high-temperature raw meal is subjected to decarbonation fraction 1-60 mm which, before being fed to the firing in a rotary kiln, is ground without cooling.

Carrying out high-speed high-temperature at 1150-1350 ^о С decarbonization of the raw material mixture in the form of a crushed material of a fraction of 1-60 mm allows to exclude granulation of the raw mixture before high-temperature decarbonization, which reduces energy consumption, and grinding the material in heated to 1150-1350 ^о С allows to increase the grindability of the material by 2-3 orders of magnitude, which reduces energy consumption for grinding.

Heat treatment of feed material fraction 1-60 mm allows it to burn with layer combustion of the solid fuel and the coolant cross-feed with a high speed of 2.5-7.5 ° ^C / s, which causes the high-intensity heat treatment at high temperature decarbonization. This interval (1-60 mm) of grain size is due to the possibility of complete decarbonization of the raw material mixture without dust removal. A decrease in grain size less than 1 mm leads to dust removal, which is irrational, and an increase in the size of a piece of material more than 60 mm is irrational due to a decrease in the degree of decarbonization.

Production grinding at temperatures below 1150 ^C. irrational because it reduces the degree of decarbonization of raw mixture and increasing its energy consumption for grinding.

Increasing the temperature over ¹³⁵⁰ C irrational, since at higher temperatures the formation of calcium silicates, which leads to particle aggregation and sticking of the raw mix, leading to shutdowns and contributes to an increase of grinding power consumption. In addition, milling at higher temperatures is technically difficult.

Production grinding at 1150-1350 ^C. previously decarbonated material allows no heat losses between the rotary kiln and precalciner to reduce energy consumption for the grinding of raw materials as compared with the prototype to 45-70%
The raw material mixture in the form of crushed material of a fraction of 1-60 mm is fed to high-temperature decarbonization, the product of decarbonization, losing 30-35% of the initial mass during heat treatment at 1150-1350 ^о С, is fed to the grinding, which is conducted without cooling, and then the ground mixture is fed into a rotary kiln, where it is finally fired to obtain a cement clinker, which is then fed for cooling. Furnace gases are fed to high-temperature decarbonization and, giving their heat to the material, the gases are removed to dust cleaning.

 To implement the method, a mixture of the following chemical composition was prepared, which are presented in table 1.

 The material was crushed, the particle size distribution of the mixture is given in table.2.

The grinding of the crushed raw material mixture was carried out in the following sequence: heat treatment in a decarbonizer of rapid cross-firing type (as a result of this, the raw material mixture lost 35-45% of its original mass due to the removal of CO ₂ and hydrated water), grinding at 1150-1350 ^о С, firing in rotary kiln, clinker cooling in the refrigerator. During the grinding, electricity was recorded, the degree of decarbonization of the crushed raw material mixture was determined. The determination of the decrease in the specific energy consumption per 1 ton of clinker due to grinding of decarbonized crushed raw materials was carried out by calculation. The test results are shown in table.3.

EXAMPLE Example 1. As a raw material taken crushed (Tables 1 and 2) and milling was carried out at ²⁰ ° C without pre-decarbonization (the prototype).

PRI me R s 2-6. Crushed raw materials, the characteristics of which are given in table. 1 and 2, is subjected to decarbonization at 1100-1400 ^about With in a decarbonizer high-speed firing, and then grinding. Final firing is carried out in a rotary kiln, and cooling in a cross-fridge. The test results are shown in table.3. As can be seen from table 3, the optimal temperature range at which the grinding is performed is the interval 1150-1350 ^about C.

 Thus, the production of grinding pre-decarbonized raw materials can reduce the energy consumption for grinding by 1.8-2.7 times.

Claims (1)

METHOD FOR PRODUCING A CEMENT CLINKER, including preparation of a raw mixture, its grinding, high-speed high-temperature decarbonization at 1150 - 1350 ^o С, firing in a rotary kiln and cooling, characterized in that, in order to reduce energy consumption for grinding, high-speed high-temperature decarbonization is subjected to a raw mix 60 mm, which is grinded without cooling before being fed to the firing.

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